Problem: $-4vw - 9vx + 9v - 7 = w + 5$ Solve for $v$.
Explanation: Combine constant terms on the right. $-4vw - 9vx + 9v - {7} = w + {5}$ $-4vw - 9vx + 9v = w + {12}$ Notice that all the terms on the left-hand side of the equation have $v$ in them. $-4{v}w - 9{v}x + 9{v} = w + 12$ Factor out the $v$ ${v} \cdot \left( -4w - 9x + 9 \right) = w + 12$ Isolate the $v$ $v \cdot \left( -{4w - 9x + 9} \right) = w + 12$ $v = \dfrac{ w + 12 }{ -{4w - 9x + 9} }$